Ultra-Intensive and Ultra-Wideband Electric Field Sensing System With LiNbO3 Integrated on Fiber Tip

The measurement of ultra-intensive transient electric fields is essential for analyzing many extreme physical phenomena. However, it is still challenging for conventional electronic systems to measure both the ultra-intensive and ultra-wideband electric fields. In this paper, we report an ultra-intensive and ultra-wideband electric field sensing system with a lithium niobate (LiNbO3, LN)-integrated electro-optic probe and an all-fiber optic demodulation module. This electro-optic probe can transform electric field variations into light polarization state changes, and an all-fiber optic demodulator converts this into intensity changes for photodetector detection. The sensing system is theoretically capable of having a 23 GHz bandwidth, a 65 dB dynamic range, and a maximum measurable field of 3.16 MV·m−1. Experimental results show that the system exhibits a wideband response ranging from 50 Hz to 20 GHz, a maximum measurable electric field of 2.83 MV·m−1, and a dynamic range of 63 dB, approaching the theoretical design limit. This system also achieves a sensitivity of 0.65 V/m·Hz−1/2 and an electric field responsivity of 0.2975 mV/(kV·m−1). Furthermore, the electro-optic probe has a compact structure with a size of 2 × 2 × 12 mm3, enabling stable and non-destructive measurement of applied electric fields. The system can be used in complex electromagnetic environments, such as lightning measurement.